Current Ununtu versions are disabling a security feature that was added to the GNOME desktop environment last year.
Thumbnail parsers are scripts that read files inside a directory and create thumbnail images to be used with GNOME, KDE, or other Linux desktop environments.
This operation takes place every time a user navigates to folders, and the OS needs to display thumbnails for the files contained within.
In recent years, security researchers have proven that thumbnail parses can be an attack vector when hackers trick a user into downloading a boobytrapped file on their desktop, which is then executed by the thumbnail parser [1, 2, 3].
It's for this reason that the GNOME team added Bubblewrap sandboxes for all GNOME thumbnail parser scripts last year.
But according to German security researcher and journalist Hanno Boeck, the Ubuntu operating system is disabling Bubblewrap support inside GNOME for all recent OS versions.
But there's a valid explanation for what Ubuntu is doing, according to Alex Murray, Ubuntu Security Tech Lead at Canonical.
Murray says the Ubuntu team opted to disable GNOME's Bubblewrap because they did not have the time and resources to audit the feature.
"Bubblewrap is relatively new software doing some complicated things to set up sandboxes," Murray said. "If we just blindly promote it to [Ubuntu main] and then find out it has a vulnerability itself which we could have caught through code review beforehand that is not a good outcome for our users."
"It's easy to criticise but the reality is that to ship a high-quality distro all packages promoted to [Ubuntu main] have to go through a thorough review process which takes time," Murray added.
"It will likely get there soon, but the security team has limited resources and with 2018 being the year of a whole new class of vulnerabilities with seemingly no end in sight (aka Spectre, etc.) everyone just has to be patient."
Article was updated to remove mentions of CentOS. A CentOS developer clarified that the reason why CentOS appeared to disable Bubblewrap was because CentOS was shipping GNOME 3.22.2, an older version where Bubblewrap wasn't included. Title updated accordingly. Bleeping Compute regrets the error.